The [type=NameOfMob] (ex. : /execute @e[type=Chicken] ~ ~ ~ say Test

The [type=NameOfMob] (ex. : /execute @e[type=Chicken] ~ ~ ~ say Test)

What I expected to happen was...:
What I expected was that all the chickens will say Test

What actually happened was...:
What actually happened is an error message

Steps to Reproduce:
1. Run Minecraft 1.8
2. Run /execute @e[type=Chicken] ~ ~ ~ say Test
3. Run Minecraft 1.8.1
4. Run /execute @e[type=Chicken] ~ ~ ~ say Test